The present invention relates to a dispenser for feeding blocks of adhesive into a glue melt tank.
A conventional method of performing this process involves adding such blocks to the tank by hand. The molten adhesive in the tank is at a high temperature, and the addition of solid blocks to the molten adhesive can cause hot melted adhesive to splash out of the tank, potentially burning the person performing the addition. Clearly, a more remote method of adding the adhesive blocks would be beneficial to the interests of safety.
A previously proposed apparatus for remotely adding adhesive blocks to a glue melt tank comprises a conveyor belt to transport a quantity of adhesive blocks and automatically dispense them into a melt tank. However, such a device takes up considerable space, and is costly, so it is therefore not very practical for use in situations with limited space, a low consumption of adhesive, and/or needing a number of such systems.
Consequently, the present invention aims to provide an adhesive dispenser of a more compact size, and simpler construction to minimise costs.
Accordingly, the present invention is directed to an adhesive dispenser for feeding blocks of adhesive into a glue melt tank, comprising a magazine divided into a plurality of segments, each segment adapted to contain a block of hot-melt adhesive; a plate below the magazine having an aperture substantially the size of a segment; a side wall surrounding the magazine; drive means for moving either the magazine or the plate; and indexing means to control the drive means so that each segment is brought in turn into alignment with the aperture in the plate. This arrangement has the advantage of providing an adhesive dispenser of compact size and simpler inexpensive construction, which may be readily used in conjunction with existing glue melt tanks.
Advantageously the magazine has a carousel structure with radial segments. This has the advantage that the device is considerably more compact and the magazine only has to be supported in one place. Also it allows simple rotational movement to dispense the blocks.
In a preferred embodiment the drive means comprise an axel which rotates either the plate or the magazine, and a drive system attached to the axel.
Advantageously, the drive system is a pneumatic cylinder.
Preferably the plate is fixed and the magazine is movable. Alternatively, the magazine is fixed and the plate is movable. A movable magazine is especially advantageous as the drive means can be mounted below the plate, and hence not interfering with loading of the magazine, and the adhesive blocks also originate from one position.
In a preferred embodiment, the dispenser is further equipped with a level sensor to indicate the level of adhesive in the tank. This has the advantage that the dispenser monitors the level of adhesive in the tank, ensuring that it will not accidently become empty.
Advantageously the level sensor triggers the indexing means to add more blocks. Thus more adhesive blocks are fed to the tank, and the level of adhesive in the tank is maintained at constant level.
Advantageously, the level sensor is equipped with a timer. The operator of the dispenser can therefore readily be informed if the level of adhesive in the melt tank becomes static, which could indicate a malfunction of the dispenser.
Preferably the timer is equipped with an alarm which is set off when a predetermined level of adhesive has been reached or has been maintained for a predetermined period of time. This situation occurs when the dispenser is empty and unable to feed further blocks to the melt tank. The alarm is therefore advantageous in that the operator is made aware that the dispenser requires more adhesive blocks and can attend to this, so that the apparatus using the adhesive is kept operational.
Alternatively, the indexing means is equipped with a counter to indicate the number of adhesive blocks dispensed. The operator can therefore readily be provided with information regarding the number of adhesive blocks consumed.
Preferably the counter is equipped with an alarm which is set off when the adhesive dispenser approaches or reaches an empty state. This provides the advantage that the operator is warned that the dispenser requires more adhesive blocks.
In a preferred embodiment, a removable lid closes the top of the adhesive dispenser. This arrangement provides a barrier between the operator and the molten adhesive, and consequently reduces the possibility of burns, and reduces the risk of extraneous objects being introduced into the dispenser.
Preferably fixing means are provided to allow the lid to be secured in the closed position. The lid cannot therefore be accidently knocked off the dispenser, or removed by unauthorised personnel.
Advantageously the lid or fixing means incorporate a switch coupled to the indexing means which stops the drive means when the lid is open. This arrangement is greatly advantageous in terms of safety, since it means that the dispenser is rendered inoperable if the lid is not in the closed position, so the dispenser cannot be used without a lid, nor can it be filled whilst it is working.
Advantageously, a number of carousels and plates are stacked alternately one above the other and linked with an extended axel. The dispenser can hence be configured to hold as many adhesive blocks as meet the requirements of the adhesive consumer, for instance for the length of a full shift or day.
Additionally, the segments of the magazine and the aperture in the plate can both be adapted to accommodate more than one adhesive block. Therefore, a greater quantity of adhesive can be delivered to the melt tank at one time.